Ellie Simmonds sat on the sofa at her home in Walsall in the days after the Paralympics, the roar of the Aquatics Centre willing her to her first and most memorable gold medal of the Games reduced to a muffled, precious memory.   At 17, before most of her peers had even decided on a career, she accepted that the defining moment of hers had probably been and gone. ‘I was on a serious low,’ said Simmonds.

‘I sat around for a few days, maybe even weeks. I became a real sofa person. I considered whether I actually wanted to swim any more and thought, “I don’t know what I want to do, I don’t know if I can be bothered to do anything at all”.

‘For four years I was consumed by London and I thought, “Now it’s over, what have I got to look forward to?” I don’t think anything can replicate that feeling of winning gold in the 400metres free, to be honest. It’s never going to get better than that and Rio seemed so far away.’

Her ‘love for winning’ was too much to keep her from the water for long and she has committed to the next Paralympic cycle, easing herself back into training with coach Billy Pye.

She balances six sessions a week in the pool with sixth form at Swansea’s Olchfa Comprehensive. Swimming took precedence last year to the extent that Simmonds did not perform as strongly in her AS levels as she expected.

It is difficult to maintain grades when you have just been included among the 12 nominees for BBC Sports Personality of the Year at the end of the greatest summer of sport this country has seen.

The invitations – to parades, product launches and film premieres – or, as Simmonds calls it, ‘the bonus stuff’, have arrived in their hundreds.

In the two months since the Paralympics, Simmonds has met the Queen, the Duchess of Cambridge and Daniel Craig.

At Paris Fashion Week, Simmonds was front row for the Stella McCartney show, flanked by Victoria Pendleton and Louis Smith.

‘Stella gave me a dress to wear for an event. She did such a good job on our kits and I love her handbags, so it was lovely that she invited me to Paris,’ said Simmonds.

‘This year has been all about London and at this point you should step back and enjoy it and make the most of all the opportunities you get. I love swimming and that’s what I am, a swimmer. All these added things are just bonuses. I don’t do it for that but it’s so exciting. I went to the James Bond premiere and have filmed a few TV shows that are out early next year.’

Simmonds is most animated when she talks about the surprise party her family planned for her 18th birthday last month and a promised trip to New York, on hold until the new year.

‘I met up with my best friend in the morning,’ said Simmonds.

‘I asked if she wanted to do something that evening and she said she was busy. I went for a nap and the next thing I knew there was a hog roast man outside and 40 of my family and my friends were there. It was one of the best things ever.’

This week, it was back to work and administering a British Swimming masterclass at Wales National Pool in Swansea. A line of children had their faces pressed against the gallery window, straining to catch a glimpse of her at the water’s edge.

“Ellie’s here,’ said the receptionist, qualifying the level of hysteria to a customer.

Like Jessica Ennis, Mo Farah and Bradley Wiggins, Simmonds has become a one-name sports star in these parts. Emily Else is 10 and has cerebral palsy.

Like Simmonds, she began swimming in able-bodied classes as a five-year-old. ‘I was star-struck when I saw Ellie in the flesh,’ she said.

‘It’s so inspirational to talk to her and she gave us lots of advice.’

Simmonds faces different challenges in the water from Emily. But nothing could be more instructive of the bloody-minded determination required to win than Simmonds’ 400m freestyle final this summer.

It was her first encounter with American Victoria Arlen, a fellow 17-year-old who had arrived on the scene just two months earlier after being paralysed below the waist by a virus.

Confusion surrounded Arlen’s classification and she was confirmed on the start list just two hours before the race.

‘That’s the thing with Paralympic sport,’ said Simmonds.

‘Someone might have an accident a year earlier and then be placed in my S6 category. I just had to presume she would always be competing and prepare accordingly.’

Any doubts about how competitive and thrilling Paralympic sport can be evaporated as she overhauled Arlen in the final length.

‘I’ll remember that feeling forever,’ said Simmonds. ‘All the pain that you go through in training and in the race. To touch and it all just disappears. I felt all the relief, pure pleasure.’

Simmonds thinks the often talked of ‘legacy’ of the Paralympics can be split into two parts – the first being access to sport for disabled people; the second, a positive change in the perception of disabled people among the wider public.

‘Channel 4 did such a good job with the coverage and I think it showed the public that we’re just normal athletes with a disability,’ said Simmonds.

‘Having three Paralympians nominated for sports personality [David Weir and Sarah Storey are also up for the award] is amazing.

‘For me, it is a huge honour. I hope that one day a Paralympian could win it, I don’t see why not.’

Simmonds talks breezily about fashion and friends as she drives me back to the train station; the pedal extensions, raised floor and cushion support in her Mini One the only reminders of her disability.

The CDs strewn on the floor, a scented air freshener hung above the dashboard, giggling about boys and talk of Ugg boots for Christmas offer a far better insight into the real Ellie Simmonds, a normal teenage girl with extraordinary ability.

Ellie Simmonds is a member of the British Gas GBR Disability Swimming Team. British Gas has been the principal partner of British Swimming since 2009 and is encouraging everyone in Britain to discover the benefits of swimming. For more info, visit www.facebook.com/BGSwimming